In conveyor systems for articles such as cans or bottles, it is often desired to combine a mass of articles into a singe file lane. One way of accomplishing this is to provide a stationary guide above the conveying surface which is aligned at an angle with respect to the direction of travel of chains, belts or other surfaces at increasing speeds to urge the articles toward the single file lane. With this type of passive system, however, the articles often become jammed at the single file lane requiring them to be cleared and possibly damaging equipment.
Jamming is frequently caused by articles which have been knocked over or "downed" during the single file combining process. Downed articles are knocked over when they contact the stationary guide. Articles which bounce off the guide may also knock over articles which have not yet reached the guide.
One prior art attempt at solving the problem of articles knocking down when they contact the single filing guide is illustrated in FIGS. 4-5. In this prior art device, the multiple conveying surfaces are air previous and advance over a vacuum chamber. A disadvantage of this prior system is that the vacuum impedes transference of articles from one conveying surface to an adjacent conveying surface in a direction toward the single file lane, retarding maximum article throughput. A further disadvantage of this prior system is that a large and costly vacuum pump is needed to apply a sufficient vacuum on the conveying surfaces so that articles are not knocked over when they strike the guide.
The details of constructing detail of the device illustrated in FIGS. 4-5 give rise to another disadvantage which is the complexity and therefore the cost of manufacture. The conveying surfaces of this device are formed of "table top" chain having rigid links and supported from below by a pair of spaced apart wearstrips. Making, aligning, supporting and assembling the wearstrips required for a plurality of adjacent conveying surfaces can be a significant expense.
Other known prior art conveyors including those disclosed in U.S. Pat. Nos. 4,669,604; 4,768,643 and 3,352,404, include a single belt advancing over a single vacuum chamber. The conveyer combiner systems of both the 4,669,604 and the 4,768,643 patents include a deadplate (32) and (12), respectively, for accumulating cans in diagonal rows (U.S. Pat. No. 4,669,604) or in a contiguous equilateral triangle (U.S. Pat. No. 4,768,643) prior to single filing them on a vacuum belt.
U.S. Pat. No. 5,311,979 discloses a vacuum combiner system which comprises one or more conveyer belts (30-34) which may be operated at the same or different speeds and with the same or different vacuum chambers for each belt. Inwardly extending guides which may include rollers and/or downstream air jets are also disclosed.
What is desired, therefore, is an article combiner which minimizes the knockdown of articles when they strike the guide but which does not impede transfer of articles between conveying surfaces toward the single file. An article combiner which is relatively inexpensive to manufacture and easy to assemble is also desired.